Treatment of hydrocarbon oils



Nov. 9, 1943. B. s. FRIEDMAN TREATMENT 0F HYDROCARBON OILS Filed Jan.51, 1941 llllu 'II'III FRIEDMAN INVENTOR BERNARD S'.

' cation.

Patented Nov. 9, 1943 v V =UNITED STATESk PATENT OFFICE TREATMENT oFmnocAaBoN oms Bernard S. Friedman, Chicago, Ill., assignor to UniversalOil Products Company, Chicago, Ill., a corporation of DelawareApplication January 31, 1941, Serial No. 376,723 9 Claims. (Cl. 19e-52)This invention relates broadly to the treatment a correspondingstraight-run fraction in the presof relatively heavy petroleum fractionscontainence of said gases, fractionating the products ing substantiallyno gasoline to convert them into from the aromatization treatment toproduce substantial yields of gasoline of relatively high gases,gasoline and intermediate refluxes, coolanti-knock value. In a morespecific sense, the ing and condensing said gasoline, and returning,invention is concerned with a combination of lnsaid gases andintermediate refluxes to further ter-related steps involving apreliminary crackcatalytic cracking. ing of a hydrocarbon fractionfollowed by the se- Features of the invention will be developed morelective treatment of a fraction from the rst step in detail bydescribing a characteristic operation under conditions designed toincrease its 'antil0 in connection with the attached diagrammatic knockvalue to an unusual degree. Other spe- -drawing` which shows in generalside elevation, cinc features emphasizing the value of the combiwithoutregard to exact proportion, a system of nation will be developed in thefollowing speciflinterconnected units in which the process may I beconducted. t

The art of converting the heavier fractions of Referring t0 the drawing.a $17001! fOr treatment petroleum into gasolinexby the use of heat,pressuch as a gas oil is introduced to the plant through ,sureandcatalyst is extensive and many combinaline i containing valve 2 to acharging Pump 3 f tions of processes and apparatus have been dewhichdischarges through a line 4 containing veloped which are applicable todiiIerent types of valve 5 into a heating element 6 disposed torecharging stocks. The higher anti-knock value ceive heat from furnacel. Intermediate reiiuxes of cracked gasolines compared. withstraight-run Originating in the succeeding fractionating steps gasolinasis due to their high content of olens, are admitted to line 4 from line3| as -will be,

- cyclic compounds both naphthenic and aromatic, later more speciiicallydescribed. During passage branched chain structure and aromatichydrocarand to some extent the presence of iso-parailins through theprimary heating element 6 the temwhich are known to have higheranti-knock charperature of the entering charge plus intermediacteristicsthan their normal counterparts. Of ates is raised'to some point fromabout 700 to the groups of hydrcarbOnS having high alltiabout 930 F. andthe pressure is maintained/by knock value the most desirable groupcomprises manipulation of valves along theline of now at a obviously theiso-paraiirls Since these are en point preferamy from about 30o to aboutsooo tirely saturated and exhibit no tendencies toward pounds per squareinch.

deterioration by polymerization ,or other con- The heated products fromcon 5 pass thmugh densation reaction. However, monooleiins of une 3containing valve g to a, primary catalytic -reactor i0 which'preferablycontains a ller of vcatalyst composed of materials fostering bothcracking and hydrogenating reactions. For example, the crackingcomponent may comprise Ysuch materials as alumina, zirconia, titania,thoria,A silica-alumina, or silica-alumina-zirconia bons have goodanti-knock characteristics and satisfactory motor fuels are in use whichcontain relatively high percentages of them. The present process is animprovement in the eld of i catalytic conversion of heavy hydrocarbonfractions to produce gasoline boilinggrange distillates hi an 1 kn k l r4 C composites, clays, either raw or acid treated, y gfIn rrliespeciiigceni'loinlxtehnpresent inveno kieSelguhr, calomed magnesite,etc., wh1lek the hytion comprises catalytically cracking interme'-drogena'ting componen-t may comprise one or more diate` boiling rangepetroleum fractions in the f the ondes or sumdes of Such metals as cmo"presence of hydrogen to produce substantial mmmfmqlybdenum' Zinctungstel?! manganese yields of gasoline therefrom, fractionating thecobalt or copper' The only essentlal of the maf' products. to producegases, gasoline fractions terial employed as a Primary catalytic reactor1s boiling up to about 300 F., a naphtha fraction that it be able. toexert both a Cracking and hy boiling from about 300 to about .400 F.,intermedrogenating action. The extent o f the' two types diateinsulciently converted fractions and re- 0f reaction may be Varied byVa'lymg the'propor" siduum, cooling, condensing and collecting saidtiOIlS 0f the ingredients of the catalyst` 00111D05- gasoline fractionboiling up to 300 F., returning tes employed. A convenient compositeincludes said intermediate' Vfractions to further catalytic a preparedalumina-'silica composite mixed with cracking, recovering said4residuum, subjecting an alumina-molybdena composite. o

said fraction boiling from 300 to 400 F. to cata Hydrogen necessary foreffecting the desired lytic aromatization treatment in the presence ofdegree of hydrogenation during the cracking of the charge is introducedfrom a source not shown through line 61 containing valve 68 to acompressor 69 which' discharges through a line 10 containing a valve 1Iinto the primary catalytic reactor. A gas mixture containing relativelyhigh percentages of hydrogen which may be fractionated to increase thehydrogen content is returned from vfractionator 49 through line 65containing valve 66. The relative proportions of hydrogen used in theprimary reaction zone and the amount of make-up hydrogen introduced fromline 61 will be varied to produce the best overall results of theprocess.

Total conversion products from primary catalytic reactor I pass throughline II containing valve I 2 to a fractionating zone I3 which isrepresented in the drawing as a single column although it may compriseany arrangement of fractionators necessary for effecting the desiredseparations. From this zone gasoline vapors of relatively low boilingpoints, for example, approximately 100 to 300 F. are removed throughline I6 containing valve I1 and condensed during passage throughcondenser I8, the cooled products passing through line I9 containingvalve 20 to a receiver 2l having a gas release line 22 containing valve23 and a liquid draw line 24 containing valve 25.

Intermediate reflux condensates amenable to further hydro-crackingtreatment are represented as being drawn from a point near the bottom offractionating zone I3 through line 26 containing valve 21 to a recyclingpump 28 which discharges through lineY 29 containing valve 30 and.thence into line 3l containing valve 32 and leading to line 4 asalready indicated. Residual material too heavy for further eicientconversion is drawn through line I4 containing valve I5.

The naphtha fraction from the primary catalytic step boiling above thepreviously mentioned fraction which was removed, and usually within theapproximate range of 300 to 400 F. or higher, is withdrawn fromfractionating zone I 3 as a sidecut through line 33 containing valve 34and passes through a heating coil 35 disposed to receive heat from thefurnace 36. In this heater the temperature of the naphtha side-cut ispreferably raised to some point from about 932 to 1112" F. while thepressure is reduced to some point below 300 pounds to bring the materialto some optimum pressure and temperature combination for its eectivecatalytic conversion in the second step of the process. Thus theheatedmroducts flow through line 31 containing valve 38 and enter asecondary catalytic reactor 4I which also receives the fixed gases fromfractionating zone I3 byway of line 39 ,containing valve 40 and aregulated proportion of straight-run naphtha analogous to that withdrawnfrom fractionating zone I3 from line 33. This latter straight-runfraction was introducedlthrough line 42 containing -valve 43 to pump 44which discharges through line 45 containing valve 46. The function ofthe secondary catalytic reactor is to aromatize the naphtha fractionsintroduced by contact with catalyst having essentially a dehydrogenatingaction. Such catalysts may comprise, for example. catalysts similar tothe hydrogenating component of the mixtures used in the primarycatalytic reactor-I0 and preferably such compounds as the oxides ofchromium. molybdenum, vanadium, tungsten. etc., representing vgenerallynumbers of theileft-hand colums of groups IV, V and VIof the periodictable. These oxides are preferably supported on relatively inertmaterialssuch as alumina, magnesia, clays, etc. In catalytic re-Product:

actor 4I the naphthenic constituents of the straight-run naphtha aredehydrogenated to form aromatics along with similar cyclic compounds ofa partially or totally saturated character found in the cracked naphthafraction in the rst step. 'I'here will also be a controlled amount ofcyclization reactions tending to convert the aliphatic constituents ofboth naphtha cuts to cyclic compounds of relatively high anti-knockcharacteristics.

The products from catalytic reactor 4I pass through line 41 containingvalve 48 to a secondary fractionating zone 49 which is preferablyadapted to separate a gaseous fraction high in hydrogen, a gasolineboiling range fraction which may be blended with the 300 F. end-pointcut from the primary fractionating zone and reiiuxes for returning tothe primary hydro-cracking step for further treatment. Thus, as shown inthe drawing the gaseous fractions from the final or secondaryfractionating zone are represented as being withdrawn through line 65containing valve 66 and returned to the primary reactor I0 while thegasoline boiling range material follows line 50 containing valve 5I,passes through condenser 52 and run-down line 53 containing valve 54 toreceiver 55 which has the conventional gas release line 56 containingvalve 51 and a liquid draw line 58 containing valve 59. Heaviermaterials suitable for further hydro-cracking treatment pass throughline 60 containing valve 6I to recycle pump 62 which discharges throughline 63 containing valve 64 back to line 3l and thence to thehydro-cracking zone.

The 300 F. end-point gasoline from receiver 2| constitutes a' goodaviation base fuel and may be used as such. The product from receiver 55from the second step is satisfactory for blending with motor fuels. Ifdesired the two fractions may be combined and the blend used as motorfuel. n

The following example is given of the results as obtained in a typicalrun according to the process of the invention although the inventionsscope is not intended to be unduly limited by the data thus presented:

A Mid-Continent gas oil was treated by passing its vapors at atemperature of 752 F. under a pressure of 700 pounds per square inchover a mixed catalyst comprising essentially a silica- 'alumina-zirconiacomposite impregnated with 2 percent by weight of molybdenum ltrioxide.Three mols of hydrogen per mol of gas oil vapors were mixed therewithand the rate of iiow over the catalyst was adjusted to correspond to aliquid space velocity of 1 per hour per volume of catalyst space. t

In continuous operation the following fractions were obtained in thefirst steps:

Once-through yield Drygas weight per cent-- 1.67 300 F. E. P. gasoline lvolume per cent..v 24.5

300-400 F. naphtha do 12.7 Recycle stock do 56.4 I Carbon weight percent-- 0.41 i.

' The'300 F. end-point gasoline Ihad an octane number of 75.5, a Reidvapor pressure of 7 pounds, a bromine number of 1, and an A. P. I.'

gravity of 66.7.

The 300 to 400 F. naphtha cut was processed l,

alumina using a temperature of 1022 F., a pressure of 50 pounds persquare inch, a, liquid space velocity of 0.5, and 3 moles of hydrogenper mole of naphtha. The original naphtha cut had an A. P. I. gravity of44.5 and an octane number of 52.5, and there Was obtained a 78.5 volumeper cent yield of 84 octane number fraction which had a Reid vaporpressure of 2.6 pounds.

By ultimate recycling of insufiiciently converted materials according tothe general process shown in the drawing there is produced a total yieldof 73% by volume of 80 octane number gasoline having an end boilingpoint of 400 F.

I claim as my invention:

1. A process for the conversion of hydrocarbon oil Which comprisessubjecting said oil to conversion in the presence of a catalyst havinghydrogenating activity vand cracking activity, fractionating theresultant vaporous conversion products to form reilux condensate and toseparate a gas fraction comprising normally gaseous Vproducts, agasoline fraction and a naphtha fraction, subjecting said naphthafraction to aromatization, fractionating the resulting products from thearomatization step to form reflux condensate and to separate a gas richin free hydrogen and a gasoline fraction, and supplying thelast-mentioned reflux condensate to the rst-mentioned conversion step.

2. The process of claim l further characterized in that at least aportion of the gas rich in free hydrogen is supplied to therst-mentioned conversion step.

3. The process of claim 1 further` characterized in that at least aportion of said gas fraction is supplied to the aromatization step.

4. The process of claim 1 further characterized in that a straight-runnaphtha is combined with the naphtha formed in the rst conversion stepand the mixture introduced to the aromatization step.

5. A process for the conversion of hydrocarbon oil which comprisessubjecting said oil to conversion in the presence of a catalyst havingcracking activity and a catalyst having hydrogenating activity,fractionating the resultant vaporous conversion products to form refluxcondensate and to separate a gas fraction comprising normally gaseousproducts, a gasoline fraction and a naphtha fraction, subjecting saidnaphtha fraction to aromatzation, fractionating the resulting productsfrom the aromatization step to form reiiuxcondensate and to separate agas rich in free hydrogen and a gasoline fraction, and supplying thelast-mentioned reux condensate to the first-mentioned conversion step.

I 6. The process of claim 1 further characterized in that saidhydrocarbon oi1 comprises a straightrun gas oil.

7. A process for the production of substantial yields of gasolineboiling range materials of relatively high antiknock values from apetroleum fraction substantially devoid of gasoline which comprisessubjecting an intermediate boiling range petroleum fraction in thepresence of hydrogen at a temperature of from about 700 F. to about 930F. under a pressure of from about 300 to about 3000 pounds per squareinch to contact with a catalyst having hydrogenating activity and acatalyst having cracking activity selected from the group consisting ofcomposites of silica-alumina and silica-alumina-zirconia to producesubstantial yields of gasoline therefrom, fractionating the products toproduce gases, a

fractions and residuum, cooling, condensing andv collecting saidgasoline fraction, returning said intermediate fractions to furthercatalytic cracking, and recovering said residuum, subjecting saidnaphtha fraction. to catalytic aromatization treatment at a temperatureof from about 932 to about 1112 F., under a pressure ofless than 300pounds per square inch in contact with an oxide of chromium in thepresence of a corresponding straight-run fraction and in the presence of.said gases, fractionating the products from the aromatization treatmentto produce gases, gasoline and intermediate reuxes, cooling andcondensing said gasoline, and returning said gases and intermediaterefluxes to further catalytic cracking.

8 A process for the production of substantial yields of gasoline boilingrange materials of relatively high antiknock values from a petroleumfraction substantially devoid of gasoline which comprises subjecting anintermediate boiling range petroleum fraction in the presence ofhydrogen at a temperature of from about 700 F. to about 930 F. under apressure of from about 300 to -about 3000 pounds per square inch tocontact with a catalyst having hydrogenating activity and a catalysthaving cracking activity selected from the group consisting ofcomposites of silica-alumina and silica-alumina-zirconia to producesubstantial yields of gasoline therefrom, fractionating the products toproduce gases, a gasoline fraction boiling up tolabout 300 F., a naphthafraction boiling from about 300 F. to about 400 F. intermediateinsufficiently converted fractions and residuum, cooling, condensing andcollecting said lgasoline fraction, returning said intermediatefractions to further catalytic cracking, and recovering said residuum,subjecting said naphtha fraction to catalytic aromatization treatment ata temperature of from about 932 to about 1112 F., under a pressure ofless than 300 pounds per square inch in contact with an oxide ofvanadium in the presence of a corresponding straight-run fraction and inthe presence of said gases, fractionating the products from thearomatization treatment to produce gases, gasoline and intermediatereuxes. cooling and condensing said gasoline, and returning said gasesand intermediate refluxes to further catalytic cracking.

9. A process for the production of substantial yields of gasolineboiling range materials of relatively high antiknock values from apetroleum fraction substantially devoid of gasoline which comprisessubjecting an intermediate boiling range petroleum fraction in thepresence of hydrogen at a temperature of from about 700 F. to about 930F. under a pressure of from about 300 to about' 3000 pounds per squareinch .to

ing and collecting said gasoline fraction, returning said intermediatefractions to further cata- 4 2,334,159 lytic cracking, and recoveringsaid residuum, subpresence of said gases. fractionating the prodjectingsaid naphtha fraction to catalytic aroucts from the aromatizationtreatment to prmatization treatment at a temperature oi' from ducegases. gasoline and intermediate refluxes, about 932 to about 1112 F.,under a pressure of cooling and condensing said gasoline. and reiessthan 300 pounds per square inch in contact s turning said gases andintermediate reiiuxes to with an oxide ot molybdenum in the presence offurther catalytic cracking.

a corresponding straight-run fraction and in the BERNARD S. FRIEDMAN.

